Drilling machine



Feb. 26, 1963 v. H. NIXON 3,078,93

DRILLING. MACHINE Filed Nov. 8. 1957 5 Sheets-Sheet l Feb. 26, 1963 v.H. NIXON 3,078,932

DRILLING MACHINE Filed Nov. 8, 1957 5 Sheets-Sheet 2 FIGS FIG.4

brnawvz Feb. 26, 1963 v. H. NIXON DRILLING MACHINE 5 Sheets-Sheet 3Filed Nov. 8. 1957 Mnewraz 141F644 A. Mm

Feb. 26, 1963 v. H. NIXON 3,078,932

DRILLING MACHINE Filed Nov. 8, 1957 5 Sheets-Sheet 4 Feb. 26, 1963 v. H.NIXON 3,078,932

DRILLING MACHINE Filed NOV. 8, 1957 United Sttes sonri Filed Nov. 8,1957, Ser. No. 695,252 2 Claims. (Cl. 175-51) This invention relates todrilling machines, and more particularly to machines of the type used indrilling blast holes in mining operations.

It will be understood there is great interest in making more eflicientuse of labor and equipment in mining operations. While there have beenvarious proposals for antomatic drilling machines, it is felt there isroom for significant improvement. Accordingly, a primary objective ofthe invention is to provide a machine whereby drilling may proceed witha minimum of supervision and at optimum conditions for the particularrock or ore. Another object of the invention is to provide for quickconvenient location of the drill bit by means of simply operatedpositioning controls. A further object is to provide for convenientstarting of a hole without disturbing the controls for drill pressureand rate of feed and without requiring the miner to even up the rockface by a pick, as has been customary. Still another object of theinvention is to provide a conveniently adjusted means of controllingboth the pressure of the bit on the rock and its rate of feed, it beingunderstood that different types or hardness of rock are most efficientlydrilled under different condition of bit pressure and bit rate of feed.Other objects of the invention include the provision of a machine whichfacilitates the drilling of uniform blasthole patterns, especially as tohole depth, thereby economizing on blasting powder and achievingsuperior rock breakage as well as more efiicient drilling.

Briefly, the drilling machine includes at least one and preferably twodrilling units per operator, which units may be elevated or shiftedlaterally on the machine by power controls. Each drilling unit has along auger type drill bit coupled to a drill motor. The drill motor ismounted on a carriage, which is adapted for movement along a frame. Theframe may be tilted and swung in order to control the angle of the hole,and it may be advanced independently of the drill motor carriage inorder to facilitate starting of a hole. Hydraulic cylinders prefera-blyare utilized in advancing, tilting and swinging the frame. The machinefurther includes a hydraulic systern for advancing the drill carriage onits frame, which system is under control of adjustable pressure-reliefand flow control valves, so as to predetermine the maximum rate of feed(in soft rock) and maximum bit pressure (in hard rock). An adjustablecontrol may be provided for automatically reversing the feed motor andretracting the drill bit when the proper hole depth is reached.

In operation, elevating and lateral movement controls together with thetilt and swing controls are adjusted to locate the bit at the properposition on the rock face and at the proper angle. The drill motor isstarted, and the thrust or frame-advance control can be manipulated bythe operator to start the hole, whereupon the hydraulic feed system isactuated to take over control. This feed system permits the drilling tocontinue without operator supervision until the hole is completed andthe bit automatically retracted, whereupon the operator repositions thedrilling unit and associated bit for the next .hole.

Other features of the invention will be in par-t apparent from and in.part pointed out in the following detail de scription taken inconnection with the accompanying drawings, in which:

FIG. 1 is a side elevation of a single bit unit such as operationinvolving the use of a pick. Applicants thrust.

3,0?8,93Z Patented Feb. 26, 1963 might be used in a multiple bitmachine, the bit being fully retracted;

FIG. 2 is a top plan view of the drilling unit shown in FIG. 5 is adiagram of the hydraulic circuit used in control of this machine;-

FIG. 6 is a vertical longitudinal section of the frame showing the feedmechanism of the drill;

FIG. 7 is an electric circuit diagram;

FiG. 8 is a diagrammatic side elevation of a multiplebit drillingmachine; and

FIG. 9 is a diagrammatic top plan view of the multiplebit machine shownin FIG. 7.

Referring to the drawings, it is contemplated that a drilling machinewill be built with two or four drilling units of the type shown in FIG.1, and that two such units can be conveniently handled by an operator.unit has an anger or other type of drill 1, the auger type having spiralflights 5 for conveying the cuttings from the bit 6. The drill bit isrotated by means of an electric or other type of motor '3, and the drillpreferably is coupled to the motor through a universal joint 7 and areducing unit 9, which includes a thrust bearing and changeable gears(not shown). The gears are changed for different drilling conditions, agood selection of bit speeds being 780, 640, 520, 4 20, 350 and 280 rpm.Push button switches 11 are mounted at the operators station to startand stop the motor. hydraulic speed controls.

The drill motor 3 is mounted upon a carriage '13, which is adapted formovement along a frame 15 forming part of the bit feed-control assembly.This frame may be made up from a pair of heavy channel sections 17,joined together in spaced relationship by cross ties 19. A chain 21extends substantially the length of the frame in the space between thechannel members 17, there being a front sprocket 23 and a rear sprocket25 about which the chain is trained. The rear sprocket may be springmounted to take up slack and tension the chain, as indicated at 27. Aswill be more apparent in FIG. 6, the chain .21 is also guided aboutidler sprockets 219 to a drive sprocket 31, which is driven by ahydraulic motor system to be described. Necessarily, the drill-motorcarriage i3 is fastened at 33 to the chain, hence is advanced andretracted by the hydraulic motor unit.

It may further be noted the frame carries a fixed forward bit support 35and a travelling bit support 37. The intermediate support 37 necessarilyshould be able to advance in front of the carriage as drillingprogresses beyond the mid point and should return to the center positionas the carirage is retracted. The details of such travelling bitsupports are understood in the art, hence in the interests ofsimplifying the disclosure are not described or claimed as part of thisinvention.

Next, it will be observed the forward end of the frame.

has points 39, which are adapted to dig into the rock face and steadythe bit. The frame 15 itself is slidably mounted in angle members 41 andis pinned to a piston 43 of a hydraulic thrust cylinder 45, which isotherwise fastened at 47 'to the angle members 41. The thrust cylinder.is adapted to advanceand retract the frame 15, and

. thereby the drill bit within limits, but independently of the normalbit feed. This feature of operation is especially desirable instarting-a hole. Heretofore, it has often been necessary for theoperator to even up the rock face where a hole is to be drilled, asomewhat tedious manual Each' A hydraulic drill motor could havecylinder affords close operator control over initial movement of thebit, thereby permitting the hole to be started more conveniently whilenot disturbing the settings for the normal rate of feed orbit pressure.

Otherwise, the angle members 41 are pivoted at 49 for movement in thevertical direction under control of a hydraulic tilt cylinder 51. Thepivotal support 49, in turn, is mounted upon a column 55 for movement inthe horizontal direction under control of a hydraulic swing cylinder 57.Accordingly, the drill bit may be readily adjusted to any desired an le,vertical and horizontal, this'being desirable because blast holes areangled in order to maintain a uniform width and height at the workingface of the mine. Separate control valves 59 located at the operatorsstation are connected to the several hydraulic cylinders 45, 51 and 57so as to permit control over each cylinder.

Referring now to FIG. 5, there is a main hydraulic pump 61 supplied byan associated reservoir 63. The pump outlet is connected at 65 to ahousing 67 for the control valves 59, which control the aforementionedthrust, tilt and swing cylinders. It will be understood, the housingincludes an inlet passage to which pressure pipe 65 is connected andfrom which branch passages lead to the three separate cylinder-controlvalves 59. The hydraulic cylinders 45, 51 and 57 are of thedouble-action type, hence their control valves 59 are manual four-wayvalves, preferably operated by joy sticks. When the joy stick is movedin one direction, pressure is supplied to one end of the associatedcylinder and its other end is drained to an outlet passage in the valvehousing 67. This outlet passage is connected through a drain pipe 69 toa return manifold 71, which in turn empties through a connection 73 tothe pump reservoir 63.

The pressure side of the system is continued from the inlet passage ofthe valve housing 67 by a conduit 75 to the inlet port of an adjustablerelief valve 77. Control unit 77 is adapted to release hydraulic fluidthrough a drain 83 to the return manifold when the pressure in theoutlet port or pipe 84 exceeds a predetermined value. An adjustinghandle 79 is provided to vary the outlet pressure in accordance with thedrilling conditions, as will be explained, and the pressure outlet fromthe relief valve is connected at 84 to the inlet 81 of a three-positionfour way solenoid valve 85. Valve 85 has a pair of outlet conduits 87and 89, and the valve is actuated by solenoid means from a closedposition to either of two open positions. In one open position, theconduit 87 is fed from the inlet $1 and the conduit 89 drains throughconnection 91 to the return manifold 71, but this relationship isreversed when the solenoid valve is actuated to its other open position.

Conduit 87 is connected to what is termed the forward side of areversible hydraulic motor 93, whereas the other conduit 89 is connectedto the so-called reverse side of the motor. Accordingly, the solenoidvalve starts and stops the motor and also determines its direction ofrotation, the arrangement being such that the drill is advanced whenpressure is supplied through forward" conduit 87 and the drill isretracted when the input 81 is placed in communication with reverseconduit 89.

The connection 87 to the forward side of the motor is connected at 95 toan adjustable flow control valve 97, which is adjusted to bleed off apredetermined quantity of hydraulic fluid through a drain pipe 99 and adischarge pipe 101 to the return manifold. It will be understood thatthe main hydraulic pump 61 has a predetermined capacity or rate of flow,and that the speed of the hydraulic motor 93 or rate of bit advance isdetermined by the amount of fluid bypassed through the flow control. Inother words, the rate of bit advance is limited, the limit rate beingdetermined by the setting or quantity of hydraulic fluid bypassedthrough the flow control valve 97. Such a limit on the rate of advanceis especially desirable in drilling soft materials in order to insurethat the cutof the start-stop condition.

tings are removed by the spiral flights of the drill. If the advance istoo great in relation to the rotational speed, the cuttings willaccumulate within the hole. It may also be noted that the control overthe rate of feed applies only to the advance or forward side of themotor. In normal operation, there will be some drain off through thefiow control 97 so that the rate of advance is somewhat less than thatobtainable from the hydraulic pump. On the other hand, there is no drainoff on the reverse side of the motor unit, hence retraction will be at amaximum rate and the drilling operation thereby speeded up.

The adjustable relief valve 77 is especially desirable in drilling hardmaterials. It should be understood that this valve is responsive to thepressure on the inlet side of the feed motor 93. Should the bitencounter an unusually hard material or difficult drilling condition,the pressure relief valve 77 will function to limit the thrust forceapplied of the drill to a predetermined value, thereby protecting thebit against breakage.

T he feed motor 93 is controlled through its solenoid valve by astart-stop switch 105, a forward switch 107 and a reverse switch 109.These switches are electrically connected to the solenoid valve windingsso that the direction of bit feed may be controlled independently Inother words, the solenoid valve may be moved from a closed positionwherein the drill motor is entirely cut off from input pressure topositions in which the feed motor is either driven in the forward orreverse direction; In addition, the machine includes limit switchesmounted on the frame 15 and adapted for actuation by the drill-motorcarriage 13. A first limit switch 111 is fixed at the back of the frameand is connected to the solenoid valve so as to stop the feed motor. Theforward limit switch 13 may be adjustably positioned along the frame soas to control the depth of the drill hole, and this switch, in turn, isconnected in a way so as to reverse the feed motor, therebyautomatically retracting the hit upon completion of the hole. Thedetails of the electric circuits are conventional and will be readilyunderstood by those skilled in the art. One system is diagrammed,however, in FIG. 7.

Referring now to FIGS. 8 and 9, a multiple-drill machine is shown tohave an endless-track chassis 121 with a vertical tower 123 on which aplatform 125 is mounted for vertical movement. The platform may beelevated and lowered by means of cables 127 or in some other fashion notpertinent to this invention. The platform 125 in turn carried aplurality of drilling units and their operators. For example, there maybe four drilling units of the type described heretofore and twooperators. For further convenience in locating the bits, the tower 123may be adapted for rotation about a vertical axis on its chassis 121,and the platform 125 might be adapted for sidewise movement, withinlimits.

In operation, the chassis 121 is moved into position opposite the miningface and the platform 125 is elevated to a position for drilling a firstrow of four holes, but before the platform is elevated out of reach, itwould be desirable to set the positions of the forward limit switchesfor the desired hole depth. The operator may then manipulate the manualvalves which control the tilt and swing of hydraulic cylinders for eachdrilling unit to set the drills at proper angles with respect to theface. If there is a hole-starting problem, the operator may furthermanipulate the thrust cylinder control while the hole is started, thethrust cylinder otherwise being actuated to drive the frame 15 againstthe rock face so as to steady the drilling unit. The drill motor isstarted and the feed motor is also started in the forward direction. Atthe beginning of a drilling operation, it may be necessary to vary theadjustments for the rate of feed and bit pressure, but normally theseparticular settings need not be disturbed except on rare occasions.Also, the hole depth setting would not be changed, except on rareoccasions.

Accordingly, the actual drilling of a hole is substantially automatic,the feed motor being reversed and the bit retracted when the properdepth is reached. The operators task is reduced largely to that oflocating the drills in accordance with the desired blasting patternafter completion of one set of holes. Since the relative locations ofthe four drills, the angles and depths of the holes drilled are allmaintained by the machine, a more uniform drilling pattern is assured.In this respect, it will be understood that a row of four holes would bedrilled at one level, the platform then elevated to drill a similar rowof holes, etc. to the top of the mine face. If the mine face is widerthan that required for four drills, then the entire machine may be movedon its chassis to another position and the process repeated.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. In a rock-drilling machine having a frame, a drill carried by theframe for travel therealong, a fluid-actuated reversible feed motorhaving forward" and reverse" lines and adapted to move the drill alongthe frame, and a constant-flow pump having supply and return lines; theimprovement that comprises a three-position main control valve connectedto the supply and return lines of the pump, said feed motor having itsforward" and reverse lines connected to the main control valve, the maincontrol valve being movable from a stop position wherein the pump supplyline is disconnected from both the forward and reverse lines of themotor to a forward position wherein the supply line of the pump isconnected to the forward line of the motor and the reverse line of themotor is connected to the return line of the pump thereby to advance thedrill, the main control valve also being movable from the stop positionto a reverse position wherein the motor connections are reversed,thereby to retract the drill, and an adjustable by-pass valve connectedonly between the forward line of the motor and the return line of thepump, thereby to bleed E a predetermined selected quantity of theconstant pump flow,

whereby control of the rate of drill advance is reduced to a pre-setvalue when the main control valve is in the forward position withoutlimiting the rate of drill retraction when the main control valve is inthe reverse position.

2. A rock-drilling machine as set forth in claim 1 further including asolenoid means for actuating the main control valve between itspositions, forward, stop and reverse switches connected for actuatingthe solenoid means and thereby the valve to its respective positions, alimit switch on the forward end of the frame for engagement by the drilland connected to actuate the solenoid means and valve from the forwardto the reverse position, and a second switch at the back of the frameconnected to actuate the solenoid and valve from the reverse to the stopposition.

References Cited in the file of this patent UNITED STATES PATENTS1,911,138 Clute et al May 23, 1933 1,986,848 Perry Jan. 8, 19351,990,052 Sosa Feb. 5, 1935 2,288,543 Paget June 30, 1942 2,320,874Lehman June 1, 1943 2,388,720 Wright Nov. 13, 1945 2,459,902 Tucker Jan.25, 1949 2,594,098 Vanderzee Apr. 22, 1952 2,655,006 Hoen et a1. Oct.13, 1953 2,750,155 Nixon June 12, 1956 2,754,085 Sewell et al. July 10,1956 2,766,012 Hale Oct. 9, 1956 2,791,399 Curtis et a1 May 7, 19572,867,412 Hurd Jan. 6, 1959 2,895,715 Stenuick July 21, 1959 2,905,440Gerentes Sept 22, 1959 2,905,441 Poundstone Sept. 22, 1959 2,958,514 LeeNov. 1, 1960

1. IN A ROCK-DRILLING MACHINE HAVING A FRAME, A DRILL CARRIED BY THEFRAME FOR TRAVEL THEREALONG, A FLUID-ACTUATED REVERSIBLE FEED MOTORHAVING "FORWARD" AND "REVERSE" LINES AND ADAPTED TO MOVE THE DRILL ALONGTHE FRAME, AND A CONSTANT-FLOW PUMP HAVING SUPPLY AND RETURN LINES; THEIMPROVEMENT THAT COMPRISES A THREE-POSITION MAIN CONTROL VALVE CONNECTEDTO THE SUPPLY AND RETURN LINES OF THE PUMP, SAID FEED MOTOR HAVING ITS"FORWARD" AND "REVERSE" LINES CONNECTED TO THE MAIN CONTROL VALVE, THEMAIN CONTROL VALVE BEING MOVABLE FROM A STOP POSITION WHEREIN THE PUMPSUPPLY LINE IS DISCONNECTED FROM BOTH THE "FORWARD" AND "REVERSE" LINESOF THE MOTOR TO A FORWARD POSITION WHEREIN THE SUPPLY LINE OF THE PUMPIS CONNECTED TO THE "FORWARD" LINE OF THE MOTOR AND THE "REVERSE" LINEOF THE MOTOR IS CONNECTED TO THE RETURN LINE OF THE PUMP THEREBY TOADVANCE THE DRILL, THE MAIN CONTROL VALVE ALSO BEING MOVABLE FROM THESTOP POSITION TO A REVERSE POSITION WHEREIN THE MOTOR CONNECTIONS AREREVERSED, THEREBY TO RETRACT THE DRILL, AND AN ADJUSTABLE BY-PASS VALVECONNECTED ONLY BETWEEN THE FORWARD LINE OF THE MOTOR AND THE RETURN LINEOF THE PUMP, THEREBY TO BLEED OFF A PREDETERMINED SELECTED QUANTITY OFTHE CONSTANT PUMP FLOW, WHEREBY CONTROL OF THE RATE OF DRILL ADVANCE ISREDUCED TO A PRE-SET VALVE WHEN THE MAIN CONTROL VALVE IS IN THE FORWARDPOSITION WITHOUT LIMITING THE RATE OF DRILL RETRACTION WHEN THE MAINCONTROL VALVE IS IN THE REVERSE POSITION.